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Forskarna har ännu inte använt lika mycket tid till att studera alger, som de har studerat landväxter. Detta är helt naturligt då det är lättare att gå ut och hämta en synlig växt i naturen än en växt i havet, som inte syns från land och som kanske ligger djupt ner. Det finns mycket att upptäcka om algerna och många frågor, som man kan fundera över.

Alger växer praktiskt tagit överallt utom där det är så mycket is, att algerna inte får fäste. Man hittar dem vid sandstranden, på stenar och på stranden, där de flutit upp. De alger som visas i mitt häfte finns alla på ön Rörö i norra skärgården utanför Göteborg. Man kan finna dem utmed hela västkusten från Kullens Fyr i söder till  Kosteröarna i norr. Om man vill plocka alger är den bästa platsen en stenig och bergig strand, då algerna måste fästa i något som är fast. Det bästa tillfället är vid lågvatten. Alger hittas också utmed sandstränder och då handlar det oftast om alger, som har flutit upp på stranden. Ofta finns det mycket alger efter det har varit storm. Under dagarna efter stormen kan alger flyta i vattnet och upp på stranden.

Har du gått på strandkanten och sett vad som har flutit upp på stranden och kanske undrat. Vad kan detta vara? Har du sett dem växa på stenar och berg? Har du undrat över lukten? Dessa växter är alger och de kallas för havsalger. Ordet alger kommer från det latinska ordet ”algae”, som betyder vattenplanta. Tusentals olika sorters av havsalger växer i haven runt vår jord. De växer på berg, på stenar, på skal, på djur och stockar och på broar och gamla skeppsvrak, det vill säga de växer på allt de kan sätta sig fast på. Man kan också hitta dem i solen på stranden, där man badar. En del alger växer på djupt vatten och en del växer lite närmare stranden. De växter som finns i havet består till övervägande del av alger. Alger har inga frön, rötter, stjälkar eller blad. De kallas för bålväxter, då de tar upp den näring de behöver direkt ur det omgivande vattnet. Till algerna hör bland annat de stora bruna tångarterna. Algerna brukar indelas efter sina färger: grönalger, brunalger och rödalger. Man kan också dela in algerna efter deras storlek. Alger finns i olika storlekar. En del är så små så man behöver mikroskop för att se de. Andra är lika stora som de högsta träd. Makroalgerna är stora: tång-, brun- och grönalger. Mikroalger är mycket små till exempel plankton, mikroskopiskt små encelliga växter, som svävar i vattnet. Om de blir tillräckligt många säger man att de ”blommar”. Så kallad planktonblomning är bara höga halter av mikroalger. till mikroalgerna hör bland annat  den berömda Spirulinan, som är mycket proteinrik. Brunalger och rödalger är viktiga, eftersom de finns i stor mängd i havet och är rika på spårämnen. Det finns inga giftiga alger, men de kan smaka olika. Så ryck gärna av en och ät. De som brukar kallas ”giftalger” , är egentligen inga alger alls utan liknar mer bakterier. Algerna finns i olika former. De kan se ut som tjocka rep, piskor, trådar, garn, löv, händer, fjädrar eller blomblad. Några har täta grenar, andra är mindre täta. Några grenar är smala och några är tjocka. Några alger är så tunna så du kan se rätt igenom. När man plockar upp en alg är det inte alltid så lätt att se vilken grupp den tillhör. Den kan ha ändrat färg på grund av ålder eller på grund av solljus. Grönalger kan exempelvis bli vita, när de ligger i solen. Några brunalger kan bli svarta eller gula, men ändå tillhör de brunalgerna. Rödalger varierar också i färger och kan vara orange, lila, ljusröda eller vita. Om man har samlat alger ett tag kommer man att blir mer medveten om olika skillnader på alger som form, storlek, färg och hur färgerna ändrar sig. Efter ett tag kan man kanske också se, vilken grupp algerna tillhör. På något sätt är algerna som växterna på land. De växer som skogar eller var för sig. Precis som skogen är hem för många djur, är algerna hem för många havsdjur. I skogen kan fåglar och djur gömma sig och landväxter är mat för djuren. I havet är algerna mat för en del fiskar och samtidigt ett skydd för de fiskar och smådjur som lever där, precis som djuren på land behöver skydd. Men det finns en del viktiga skillnader på landväxter och växter i havet. Alger kan bara stå upprätta med hjälp av vattnet. Har dom inte vattnet faller dom ihop. Landväxter får sin näring genom rötterna, som de har i marken. Algerna får sin näring genom vattnet, som omger algerna. Algerna har inga rötter utan de griper tag i berg eller vad de få fäste i.

Thyroid enlargement caused by low iodine content in food will often be accompanied by mental retardation if aquired early in life, even physical retardation and, in most severe cases, cretinism. Public information, social welfare and iodized salt or seaweed food can theoretically eradicate this unnecessary disease. Simple goitre is the easiest of all known diseases to prevent…… It may be excluded from the list of human diseases as soon as society determines to make the effort was stated by a pioneer in goitre prophylaxis in 1920. The statement is still valid. The goitre is still a curse. One problem is that while smallpox was definitely eradicated the day the last patient was cured, goitre can only be kept under control. Background iodine deficiency will always remain, the remedy must be set in perpetually. In our days many ambitious campaigns have a posthumous reputation as: there is little sign that the preventive programme continues to be pursued with vigour and determination. For injection of iodized oil or distribution of tablets, every single person has to be called on every six months, for iodized salt authorities must have continous control that no other kind is ever distributed within the vulnerable area, and it is necessary that people really use salt for cooking. Wherever seaweed is introduced in the right way there is at least some hope that a custom will develop, a demand will be created, which could possibly survive periods when governments give other priorities. Other andvantages are the multiple health benefit, the economic  gain that seaweed does not have to be imported into any countries bordering the sea, and the positive impact on employment, as mariculture of seaweed creates lots of job opportunities. The knowledge of seaweed as antigoitre prophylax and remedy is centuries or milleniaries old, in most countries the indroduction of seaweed for food would not mean an innovation but a revival of old customs. New is only the possibility of offering seaside resources for inland needs.

Possible application of alginate is for the inhibition of absorption of lead, the concentration of which is steadily increasing in our environment due to the anti-knock agents in gasoline, from where it contaminates food products and finally raises blood lead-level. These findings can be extended to barium, cadmium and zink and alginates are recommended as a preventive measure in areas such as the vicinity of mines and chemical plants, where a high degree of pollution from metals exists. If we include the populations of all industrial areas and all polluted large cities into the part of mankind, which could need a chemical protection for heavy metals, there are still supplies enough. A good three quarter of the world´s unexploited seaweed resources are made up by an estimated 130 million tons of brown algae, all in cold waters. This figure does not refer to the standing crop but to the potential of harvestable seaweed available at reasonably increased efforts. Largest in bulk may be the kelp and rock-weed occurrencies belonging to the genera Laminaria, Ascophyllum and Fucus in the northern Atlantic. Macrocystis, Nereocystis and various Laminariales in the northern Pacific, and Macrocystis, Durvillea och Lessonia in the southern hemisphere. The most vigorous growths of these brown algae are often found in regions with very rough climate, such as the Straits of Magellan, where storms may obstruct harvesting and rain may complicate drying. While it has previously been regarded as more or less insignificant if brown or red algae were given as a source of supplementary trace elements, vitamins and proteins, it is now evident there are important differences. The alginates of brown algae are protective against many kinds of metal poisning, due to their ability of binding certain atoms. For the same reason it is possible that certain trace metals actually present in the seaweed ash will never be released from the alginates. These may have a low natural content of strontium – they are still capable of taking up all strontium ions present in other parts of our food. Ascophyllum has a not negligible content of copper. But ewes fed dominantly on seaweed gave births to lambs with copper deficiency. Most important in this connection must be to make sure that iron is not prevented from being take up by the body in presence of alginates. That iodine is not, must be regarded as having been satisfactorily established through the experience of generations. Evidently their rock-weed fodder had not only retained unreleasably all the copper it contained, but had also absorbed all copper from other sources of food simultaneously present in the sheep intestine.

Marine algae have a high ability to concentrate metal ions from sea water. For this reason they are an outstanding source for trace elements and health-giving as food. Among the ions concentrated are also radionuclides with low concentration factors of  10 to 100 thus normally only at harmless levels. It has been suggested that hazardous or inappropriate local contamination of sea areas could be detected by assaying radioactivity in marine algae. In brown alga the ability to take up radionuclides is bases on the ability of aginic acid to form insoluble complexes with strontium. In cases when dairy products, cereals, fish or meat may be contaminated, the body uptake can be prevented by addition of alginate to the food. Alginate samples in which the ratio mannuronic acid/guluronic acid is less than 1.0 are remarkably active, inhibition reaches 89%. The strontium isotope is bound to the alginate and passes through the intestines without ever entering into the body. Highest inhibition values were found in Macrocycystis, Hedophyllum, Egregia, Laminaria, Costaria, Ascophyllum and Fucus. If the body uptake is not prevented by alginates the strontium is absorbed be the blood and deposited in the sceleton, where it may cause bone tumours or leukaemia. Alginates can even be used to reduce strontium already deposited in the bone. It is supposed that some of this is released slowly, re-secreted, possible through the bile, and then in the intestines bound by alginate and excreted, if alginate treatment is given, otherwise it is re-aborbed by the blood. Thus alginate can serve both as a preventive and a therapeutic measure. The phycocolloids of red algae do no posses this property and within brown algae is great variation. In addition to a high level of guluronate units of the alginate a certain chain length (ca 150 units polyguluronate) is essential for the highest biological activity. Suitable combinations could be looked for within the natural resources, or obtained through partial hydrolysis of the alginates.

For obvious reasons, the species at present known to  curative are found in Japanese waters. The four genera mentioned represent green, brown and red algae. A variety of species were investigated, although the first reports did not specify exactly how many, which leaves the chance open that antitumour substances may be present in a considerable number of species for all regions. Evidently the resource will not be a problem for pharmaceutical quantities. Codium och Sargassum are abundantly available in all oceans and are much in demand  for other purposes, the widespread genus Dictyopteris is consumend in many areas and the East Asian Gloiopeltis, funori, is used for silk sizing. The active substances are polysaccarids found in crude water extracts. Therefore another open question is whether a regular intake of seaweed may be prophylactic. As already mentioned such an assumption might increase the demand for seaweed for human consumption.

In folk medicine seaweeds have been used for a variety of purposes from anti-curare, cooling agent for fever, eczema, gallstone, gout, menstrual troubles, renal troubles, scabies, scrofula etc., to water purification. It appears that most of these uses have been regarded as superstition by serious therapeuts, in particular the idea that certain algas could be used as a remedy for tumours. Corsican moss, bull kelps, dulses and hypnea have been used against squirrhe tumours. Nor did the report at the international seaweed symposium that algasol, an Italian preparation had proved to be active against Walcher carcinoma, Erlich carcinoma, sarcoma 180 and Galliera sarcome create any great sensation. This decade, however, has brought a series of Japanese reports showing that Codium, Dictyopteria och Sargassum species posses substances which inhibit, to different degrees, the growth of transplanted carcinoma and sarcoma in mice. Among substances which have been identified, are funoran from Gloiopeltis.

One hundred and fifty marine algae were tested for antibiotic activity against four laboratory indicator baceteria. Sixty-six of them showed antimicrobial activity against Staphylococcus aureus or other common laboratory microbes. Also bacteria isolated from the sea were strongly inhibited by a few algae. Far over one hundred seaweed species are known to contain antibiotic substances, even when those with faint effect are first sorted out. Do these figures entitle us to hope for new substitutes for pencillin from algae? At present the answer has to be in the negative or at least hesitant; actually none of the many antibiotic substances from seaweeds is pharmaceutically utilized. On the other hand investigations into antibiotic activity of marine plants are not usually initiated in search for new drugs but from an interest in the nature of competition. In an aqueous surrounding, the organisms must have an active defence against bacteria and fungi, and against each other to keep their living space free from epiphytes as necessary and to keep their living space free from competitors. Each species has its own means in the chemical warfare on rocks and in crevices. Consequently the distribution of antibiotic activity is universal in the world of algae. Antibacterial activity is as common in algae from tropical seas as in those from varm or cold temperate waters. Within genera known for wide distribution and rich occurrencies antibacterial have been found amon the green algae.

Among possible pharmaceutical uses there is one which may change the whole pattern of seaweed harvesting and trade: tomour inhibiting substances have recently been isolated from algae. If these preliminary findings would finally result in remedies for cancer, this would not only give new hope for uncountable individuals, it would also create a new aquaculture and a new industry for the cultivation and processing of seaweed species containing such drugs. It is not unlikely that the concept that seaweed in general used as food does possess preventive properties will be brought home to the public. This speculation is mentioned because of the possibility that recent andvances might cause price development which could lead still more of tropical resources to industrial countries.